JPS60149464A - Printer - Google Patents

Abstract

PURPOSE:To increase the number of types without altering the width of fingers and also the diameter of type wheel by a method in which plural central parts on which fingers are radially provided extensionally are provided so that the types of each finger are arranged in a concentrically round row. CONSTITUTION:Central discs 10 and 11 are provided to the rotary shaft 14 of a type wheel 8 and fingers 12 and 13 are radially extended outwards. The discs 10 and 11 are set such that the types at the tips of the fingers of one central disc 10 are put between the types at the tips of the fingers of the other central disc 11, and that all the tip types of the fingers 12 and 13d are positioned on the same radial faces.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device having a type wheel consisting of a type wheel and type characters provided on the finger.

In this type of printing device, the type wheel is rotated intermittently to bring the selected type of the type to rest on the printing device, and the type hammer is used to move the selected type while the selected type is stationary in the printing position. Stamp the same type, and then move the type wheel and printing hammer along the printing line,
It is well known that the printer is stopped at the next printing position and the above printing operation is performed again. (For example, JP-A-48-101022
See publication. ) This will be explained with reference to FIG.

In the figure, paper is wound around a platen 1, and a type wheel 4 is arranged so as to be able to rotate intermittently via a ribbon 3. The type wheel 4 comprises a number of radially outwardly extending fingers 5, on which are provided typefaces such as letters, symbols, etc. 6 is a printing hammer, and 7 is its support. The type wheel 4 and the printing hammer support 7 move intermittently in the axial direction of the platen 1. As shown in the figure, the fingers 5 of the type wheel 4 are arranged in one row, and when increasing the number of characters while keeping the width of the fingers constant, the diameter of the type wheel increases, which causes inertia during high-speed printing. The disadvantage is that the moment becomes large.

In addition, when increasing the number of type characters without changing the diameter of the type wheel, it becomes necessary to reduce the width of the fingers, and in this case, a residual low frequency remains when the high-speed rotation is decelerated to a standstill.

The present invention seeks to propose a printing device having a type wheel that prevents the above-mentioned disadvantages from occurring. The invention will now be explained with reference to the accompanying drawings.

In FIG. 2, two central disc portions 10, 1.1 are attached to the rotating shaft 14 of the type wheel 8, and fingers 12.13 extend radially outward from each central disc portion. There is. 9 is the axis of the rotating shaft. each finger 12
．． 13 are bent towards each other and then oriented in the radial direction again, in which case the tip end of the fingers of one central disk 10 is oriented in the radial direction again. 11, such that all the tip characters of both fingers 12.13 lie on the same radial plane. In this case, as shown in FIG. 3, the fingers from one central disk portion 10 extend straight in the radial direction, and the fingers from the other central disk portion 11 are curved, so that the leading end of the fingers is initially It is also possible to form it so as to match the finger surface from the central disk portion 10 of the. This makes it possible to reduce the diameter of the type wheel without reducing the width of each finger, and to increase the number of fingers in the case of the same type wheel. As a result, without reducing the rigidity of the fingers,
It was possible to lower the moment of inertia of the type wheel, a feature that was extremely advantageous for high-speed printing.

In the above example, a case was explained in which there were two central disc parts, but it is also possible to use two or more central disc parts. For example, as shown in FIG. can be curved toward the central disk fingers, so that the tip surfaces of all fingers are in the same radial direction.

In FIG. 5, two rows of central disc portions are fixed to the rotating shaft 14, the shaft hole at one end of the shift arm 15 fits into the rotating shaft 14, and the shaft hole at the other end is not shown. It is loosely attached to the shift arm support shaft without fixation.

Electromagnets 16° and 17 are placed above and below the shift arm 15.
are arranged, and these electromagnets receive print signals and shift from shift 1 to
The arm 15 is vertically swung around its support shaft. As a result, the type wheel 8 is moved up and down via the rotation shaft 14 fitted to one end of the shift arm 15, and the outer stage type on the large diameter concentric circle or the inner membrane type on the small diameter concentric circle is moved to the printing position. I'll bring it. It is also possible to directly move the rotating shaft 14 up and down using an electromagnet without involving the swinging movement of the shift arm 15.

The rotary shaft 14 of the type wheel 8 is connected to a drive shaft 20 of a motor 19 by a versatile joint 18 so as to be axially movable. Shaft 31 on the other side of motor 19
A sensor 30 is attached to the motor drive shaft 20 to receive a print signal and provide a position signal for selecting a 4-type character on the type wheel 8 to the type wheel 8 via a motor drive shaft 20.

The above-mentioned universal joint 18 is configured such that, while the motor 19 and its drive shaft 20 are stationary, the type wheel 8 moves up and down within the same plane, so that the axial center between the rotating shaft 14 and the drive shaft 20 is fixed. Since the distance changes, this serves to compensate for this. This universal joint can have various configurations. The one shown in FIG. 6 has slit grooves 2 in the axial direction at both ends of the joint shaft 21.
2° 23 is provided, and the forked arm 1 is fixed to the rotating shaft 14.
The pin 24 of the forked arm 20' fixed to the drive shaft 20 is fitted into the slit groove 22, and the pin 25 of the forked arm 20' fixed to the drive shaft 20 is fitted into the slit groove 23, thereby compensating for the change in the axial center distance. ing.

In FIGS. 7 and 8, in order to make the gap between the slit groove and each pin as small as possible and to improve the alignment of the printing, there are grooves connected to the slit groove at both ends of the joint shaft 21. Notches 26 and 27 are provided, and a pressing piece 28 having a protrusion 28A that fits into these notches is pressed against the joint shaft 21 by an O-ring 29. In this way, even if the pins 24, 25 of each forked arm 14', 20' wear out, the biasing action of the O-ring 29 can eliminate the gap between each pin and the slit groove. It is of course possible to use a biasing action by a spring instead of the O-ring.

The pins 24,25 are usually line contacts and therefore have the disadvantage of being susceptible to wear. On the other hand, as shown in FIG. 9, the pin can be provided with a flat portion 32 to effect surface contact, thereby extending the life of the pin. The pin in this case must be rotatably mounted on the forked arm 14' or 20'.

10 and 11, two rows of central disk portions 10.
11 respectively extend radially outwardly from fingers 12, 13, the fingers 12, 13 of both rows are both curved in the direction of each other, and their type portions 12A, 12
B, 13A, and 13B are shown in the same radiation plane. FIG. 11a shows in broken lines one of the fingers 12 of the central disk section 10 of the front row pressed against the platen surface by the printing hammer. FIG. 11b shows in broken lines one of the fingers 13 of the rear row of central discs 11 being pressed against the platen surface.

As shown in FIGS. 11a and 11b, each finger 1 is
The distances to the centers of the type parts 12A and 13A in 2.13 are Ll and L2, and the type part 12 is located at the stamping position shown by the broken line from the axis 9 of the type wheel during printing operation.
Let the distances to A and 13A be 41 and I12.

In this case, since the position of the type on the platen surface is always constant, it must be 111=I12. When the type portion hits the platen surface, the finger 13 deflects further away from its central disc portion 11 in a direction that increases the curvature;
2 reaches the surface of the central disk portion 10 and tilts slightly to the opposite side. This movement during the printing operation of each finger 12 and 13 is caused by the fact that the central disk portion 11 of the finger 13 is located further away from the printing surface of the platen than the central disk portion 10 of the finger 12, so that it is not bent. This means that the type surface 13A is closer to the type wheel axis 9 than the type surface 12A. Therefore, in order to maintain the above 11s=I12, L
It is necessary to set l < L2. The same can be said for the printed portions 12B and 13B, although there are differences in degree.

As mentioned above, the position on the platen surface where the type is struck is always constant, so either the outer type part 12A13A is struck, or the inner type part 12B is struck.

13B, it is necessary to move the type part of each row up and down about the axis 9 of the rotary shaft 14 of the type wheel. In this case, since the lengths of the finger cantilevers up to the type portions of each stage are different, in order for each type portion to abut the platen surface at right angles, the inclination angles of each type surface must be different. This will be explained with reference to FIGS. 12 and 13. In the case where the outer type part 12A or 13A is stamped as shown in Fig. 12 =8-,
As shown in FIG. 13, in the case of stamping the inner type part 12B or 13B, the distance δ that each type part bends for printing
are equal, the deflection angle θ1 of the outer type portion having a greater distance from the rotation axis of the type wheel is smaller than the deflection angle θ2 of the inner type portion having a shorter distance. That is, θ2>θ1.

On the other hand, since the position of the platen remains unchanged, if the printing surfaces of the inner and outer printing sections are arranged parallel to each other as shown in Figure 14, it is not possible to make both printing surfaces uniformly adhere to the platen. . For example, if the platen is adjusted so that the inner type surface is evenly touched as shown in FIG. It's a hit. It is easily understood that when the platen is adjusted so that the outer type surface has a uniform contact, the inner type surface has a bottom spacing, as shown in FIG.

Therefore, if the inclinations of the printing faces of the inner and outer printing parts are shifted in advance by an angle θ2-01 as shown in FIG. It can be evenly adhered to the surface.

As mentioned above, in the present invention, the type wheel is provided with a plurality of central portions having fingers extending radially, and the type characters of each finger form a circular row concentric with the center of rotation of the type wheel. , it is possible to increase the number of characters without changing the diameter of the type wheel while keeping the width of the fingers constant.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional printing device using a type wheel, FIG. 2 is a perspective view of a double-row type type wheel according to the present invention,
FIG. 3 is a partial cross-sectional view of a type wheel showing a modified example of the fingers, FIG. 4 is a partial cross-sectional view of a type wheel of still another modified example, FIG. 5 is a perspective view of a printing device according to the present invention, and FIG.
The figure is an exploded perspective view of the universal joint used in the present invention, Figure 7 is an exploded perspective view of a modification of the universal joint, and Figure 8 is the universal joint 1- shown in Figure 7.
9 is a perspective view of a modification of the pins used in these universal joints, FIG. 10 is a partial plan view of a double-row type wheel, 11a and 11b are front and rear rows. The sectional views taken along lines A-A and B-B in FIG. 10, respectively, show the position of the stamp on the finger type part of the figure, and FIG. 12 and FIG. Fig. 14 is an explanatory drawing of a finger with parallel inner type faces, Fig. 15 to Fig. 1.
FIG. 7 is an explanatory diagram showing the state of close contact between the typeface and the platen, and FIG. 18 is an explanatory diagram of a finger having an inclined typeface. 1...Platen 8...Type wheel 9...Axes 10, 11...Central disc portion 12.13...Fingers 12A, 12B13A13B...Type portion +-''> Roboform≧1 Pu==2222 German Hill Procedural Amendment October 2, 1980 Manabu Shiga, Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 179281 2. Invention name printing device 3. Make amendments. Relationship with the case Patent applicant name (674) Ricoh Co., Ltd. 4, agent address Kaji Kogyo Building, 2-32-4 Nishi-Shinbashi, Minato-ku, Tokyo
Address: 105 units (433) 4564 Showa Date of shipment: Month, Day 6, Showa, Subject of amendment Drawing 7, Contents of amendment As attached (Engraving of the drawing, no changes to the contents)

Claims (1)

[Claims] In a printing device having a type wheel consisting of a plurality of fingers extending from a central portion and type characters provided on the fingers, a plurality of central portions are provided so that the fingers extending from the center portion do not overlap each other, and the type wheel is A type wheel having type characters arranged in a plurality of circular rows concentrically with respect to a center of rotation, a rotary drive means for rotationally driving the type wheel, and a method for selecting the plurality of circular rows. and shifting means for shifting a type wheel.